Geoparque Mundial UNESCO

Nº44 – Valle de Gualija: San Román and Marialina Mine

Geoparque Villuercas > Nº44 – Valle de Gualija: San Román and Marialina Mine

LOCATION AND ACCESS

The Gualija river begins near the village of Navatrasierra, in the middle of the Guadarranque syncline, and flows northwest until it flows into the river Tagus, today the Valdecañas reservoir, very close to the Roman ruins of the city of Augustóbriga. It owes its name (Alija river) to the fact that on its right bank, on a steep granite hill, are the ruins of the Arab castle of Alija (Hisn Alixa), a bastion on the border of the Tagus during the Reconquest.

The San Román hermitage and its Roman ruins, the olive grove and the adjoining mine are located about three kilometres south of the village of Peraleda de San Román. Access to the mine is via a path that leads directly from the village centre to the banks of the Gualija river on the right bank. Above the old olive grove you can see the outcrop of a wide quartz dyke, with the mining workings and their abandoned installations.

ATTRACTIONS OF THE VISIT

The industrial exploitation of the Marialina mine was commenced around 1871 by an English company, by means of a shaft 80 metres deep and two underground galleries located at a depth of 30 and 50 metres and 500 metres long. The last mining concession dates from 1917.

The Romans from the neighbouring city of Augustóbriga settled on the fertile soils of the banks of the Gualija, creating an extensive settlement whose remains extend around the ruined medieval hermitage of San Román. Nearby we find abundant iron slag and also a limestone quarry from which the lime needed to build the temples, walls and other buildings of Roman Augustóbriga was extracted.

GEOLOGICAL INTERPRETATION

Read Geological Interpretation

The Marialina mine is geologically located in the Ibor Group, which outcrops between the northern flank of the Guadarranque syncline and the Garvin fault. These materials are metamorphosed by contact with the important granitic intrusions of the Peraleda Batholith.

The mine is located in a quartz vein or dyke that cuts through both the granites and the metamorphic slates that border it. The mineral association is made up of quartz, barite, galena, sphalerite, chalcopyrite and malachite, obtaining lead, zinc and copper.

It can be seen how this quartz lode with industrially beneficiable metallic minerals has cut through other rock types, such as granites and metamorphic shales.